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TRANSDUCER, MECH. MEASUR. AND INDUS. INSTRU.
YEAR 2012
Q. 1
A capacitive motion transducer circuit is shown. The gap d between the parallel
plates of the capacitor is varied as d ^ t h = 10-3 61 + 0.1 sin ^1000pt h@ m . If the value
of the capacitance is 2 pF at t = 0 ms , the output voltage V0 at t = 2 ms is
(A)
(B)
(C)
(D)
Q. 2
ONE MARK
p mV
2
p mV
2p mV
4p mV
A strain gauge is attached on a cantilever beam shown. If the base of the cantilever
vibrates according to the equation x ^ t h = sin w1 t + sin w2 t , where 2 rad/s < w1 ,
w2 < 3 rad/s , then the output of the strain gauge is proportional to
(A) x
(B) dx
dt
2
(C) d x2
dt
d ^x - y h
(D)
dt
YEAR 2012
Q. 3
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TWO MARKS
A dynamometer arm makes contact with the piezoelectric load cell as shown. The
g -constant of the piezoelectric material is 50 # 10-3 Vm/N and the surface area
of the load cell is 4 cm2 . If a torque t = 20 Nm is applied to the dynamometer,
the output voltage V0 of the load cell is
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(A) 4 V
(C) 10 V
(B) 5 V
(D) 16 V
Q. 4
Water (density : 1000 kgm-3 ) stored in a cylindrical drum of diameter 1 m is
emptied through a horizontal pipe of diameter 0.05 m. A pitot-static tube is
placed inside the pipe facing the flow. At the time when the difference between
the stagnation and static pressures measured by the pitot-static tubes is 10 kPa,
the rate of reduction in water level in the drum is,
1
1
(A)
(B)
ms-1
ms-1
200 5
75 10
1
1 ms-1
(C)
(D)
ms-1
50 10
40 5
Q. 5
A U -tube manometer of tube diameter D is filled with a liquid of zero viscosity.
If the volume of the liquid filled is V , the natural frequency of oscillations in the
liquid level about its mean position, due to small perturbation, is
g
gV
(A) D
(B) 2 2
D2
p
2 2p V
(C)
gD
2 p V 1/3
1
(D) 1
p
g
D
Common Data For Questions 6 and 7 :
The deflection profile y ^x h of a cantilever beam due to application of a point
force F (in Newton), as a function of distance x from its base, is given by
y ^x h = 0.001Fx2 a1 - x k m . The angular deformation q at the end of the cantilever
3
is measured by reflecting laser beam off a mirror M as shown in the figure.
The translation S of the spot of laser light on the photodetector when a force of
F = 1 N is applied to the cantilever is
(A) 1 mm
(B) 3 mm
(C) 6 mm
(D) 12 mm
Q. 6
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Q. 7
TRANSDUCER,MECH.MEASUR.ANDINDUS.INSTRU.
If linear variable differential transformers (LVDTs) are mounted at x = 1 m and
2
x = 1 m on the cantilever to measure the effect of time varying forces, the ratio
4
of their output is
(A) 12/7
(B) 40/11
(C) 176/23
(D) 112/15
YEAR 2011
ONE MARK
Q. 8
The Treadmill test is used to diagnose
(A) The balancing style during walk of the patient
(B) the auditory activity of the patient
(C) the visual activity of the patient
(D) the cardiac activity of the patient
Q. 9
The characteristics of a thermometer measuring ambient temperature is
2 dTi + Ti - Ta = 0 , where Ti and Ta are the indicated and ambient temperatures,
dt
respectively, both in cC , and time is in second. The - 3 dB cut-off frequency in
the frequency response of the thermometer is
(A) 1 Hz
(B) 1 Hz
2
4p
(C) 1 Hz
(D) 2p Hz
Q. 10
For a copper-constantan (Type T ) thermocouple, the junction potential E (in mV)
at qcC is given by E = 38.74q + 3.3 # 10-2 q2 + 2.07 # 10-4 q3 - 2.2 # 10-6 q4 +
higher order terms, assuming the cold junction compensation. The sensitivity of
thermocouple at 100cC is approximately
(A) 45.34 mVcC
(B) 42.75 mV/cC
(C) 38.74 mV/cC
(D) 0.06 mV/cC
Q. 11
The temperature of a furnace is monitored at a distance of 50 m away. The
temperature transmitter has a range of 0-500cC and provides 4-20 mA current
output. The measured temperature and the output current have a straight line
relationship with positive slope. The temperature is determined form the voltage
measured across a resistance of 500 W in the current loop. If the voltage measured
across the resistance is 4 V, the temperature of the furnace is
(A) 100cC
(B) 125cC
(C) 150cC
(D) 200cC
Q. 12
The conventional way of expressing vibration is in term of
(A) Richter scale
(B) acceleration due to gravity
(C) speed of sound
(D) atmospheric pressure
Q. 13
The primary and secondary of an LVDT (stroke length ! 50 mm ) are connected
to a 3 kHz sinusoidal source and ideal semiconductor diode bridge-based phase
sensitive demodulator circuit. The core of the LVDT remains static at 15 mm
above the ideal null position. The frequency of the voltage observed at the input
of the low-pass filter is
(A) 1 kHz
(B) 1.5 kHz
(C) 3 kHz
(D) 6 kHz
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Q. 14
TWO MARKS
In a flapper-nozzle displacement transducer, the values of the following parameters
are given :
Diameter of the orifice
= 0.2 mm ,
Diameter of the nozzle
= 0.8 mm ,
Supply pressure
= 1.4 # 102 kPa (gauge),
Ambient pressure
= 0 (gauge).
The maximum value of the sensitivity is
(A) 4.0 MPa/mm
(B) 5.6 MPa/mm
(C) 6.4 MPa/mm
(D) 7.3 MPa/mm
Q. 15
A differential push-pull type capacitive displacement sensor (nominal capacitance
C 0 = 0.01 mF ) is connected in two adjacent arms of an ac bridge in such a way
that the output voltage of the bridge is independent of the frequency of the
supply voltage. Supply to the bridge is 1 V at 1 kHz, and two equal resistance
(R = 3.9 kW) are placed in the other two arms of the bridge. The bridge sensitivity
is
(A) 0.001 mV/pF
(B) 0.05 mV/pF
(C) 0.1 mV/pF
(D) 0.5 mV/pF
Q. 16
A turbine flow-meter is rotating at 72 rpm. The flux Y linked to the nearby
magnet and coil assembly is given by Y (q) = 3 + cos (5q) mWb , where q is the
angular position (in radian). The amplitude and frequency of the output voltage,
signal, respectively, are
(A) 4 mV and 45.8 Hz
(B) 30.2 mV and 4.8 Hz
(C) 30.2 mV and 30.2 Hz
(D) 288 mV and 45.8 Hz
Q. 17
The characteristic of a thermometer measuring ambient temperature is
2 (dTi /dt) + Ti - Ta = 0 , where Ti and Ta are the indicated and ambient
temperatures, respectively, both in cC , and times is in seconds. The - 3 dB cutoff frequency in the frequency response of the thermometer is
(A) 1 Hz
(B) 1 Hz
2
4p
(C) 1 Hz
YEAR 2010
(D) 2pHz
ONE MARK
Q. 18
Poisson’s ratio for a metal is 0.35 Neglecting piezo-resistance effect, the gage
factor of a strain gage made of this metal is
(A) 0.65
(B) 1
(C) 1.35
(D) 1.70
Q. 19
The diameters of 10000 ball bearings were measured. The mean diameter and
standard deviation were found to be 10 mm and 0.05 mm respectively. Assuming
Gaussian distribution of measurements, it can be expected that the number of
measurements, it can be expected that the number of measurements more than
10.15 mm will be
(A) 230
(B) 115
(C) 15
(D) 2
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Q. 20
TRANSDUCER,MECH.MEASUR.ANDINDUS.INSTRU.
Match the Following
P.
Radiation Pyrometer
W
Angular velocity measurement
Q.
Dall tube
X
Vaccum pressure measurement
R.
Pirani gauge
Y
Flow measurement
S.
Gyroscope
Z
Temperature measurement
(A) P-Z, Q-W, R-X, S-Y
(B) P-Z, Q-Y, R-X, S-W
(D) P-Z, Q-Z, R-W, S-Y
(C) P-W, Q-X, R-Y, S-Z
Q. 21
Q. 22
The seismic mass of an accelerometer
maximum displacement of 10 mm from
of the seismic mass is
(A) 3947.84 m/s2
(C) 314.15 m/s2
oscillates sinusoidally at 100 Hz with a
its mean position. The peak acceleration
(B) 3141.50 m/s2
(D) 100.00 m/s2
The output voltage of a transducer with an output resistance of 10 kW is connected
to an amplifier. The minimum input resistance of the amplifier so that the error
in recording the transducer output does not exceed 2% is
(A) 10 kW
(B) 49 kW
(C) 490 kW
(D) 1.2 MW
TWO MARKS
YEAR 2010
Q. 23
Q. 24
The velocity v (in m/s) of a moving mass, starting from rest, is given as dv = v + t .
dt
Using Euler forward difference method (also known as Cauchy-Euler method)
with a step size of 0.1 s , the velocity at 0.2 s evaluates to
(A) 0.01 m/s
(B) 0.1 m/s
(C) 0.2 m/s
(D) 1 m/s
A thermocouple based temperature measurement system is shown in the adjoining
figure. Relevant thermocouple emf data (in mV) is given below. The cold junction
is kept at 0cC . The temperature is 30cC in the other parts of the system. The
emf V0 is measured to be 26.74 mV. The temperature of the hot liquid is
Temperature
Emf of Chromel-Constantan
Emf of Copper-Constantan
10cC
0.591
0.391
20cC
1.192
0.789
30cC
1.801
1.196
370cC
26.549
19.027
27.345
19.638
380cC
(A) 370.0cC
(C) 376.6cC
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(B) 372.4cC
(D) 380.0cC
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Q. 25
TRANSDUCER,MECH.MEASUR.ANDINDUS.INSTRU.
A differential pressure transmitter is used to measure the flow rate in a pipe. Due
to aging, the sensitivity of the pressure transmitter is reduced by 5%. All other
aspects of the flow meter remaining constant, change in the sensitivity of the flow
measurement is
(A) 10.0%
(B) 5.0%
(C) 2.5%
(D) 2.2%
ONE MARK
YEAR 2009
Q. 26
Assuming complete dissociation, the pH of a 1 mm solution of H 2 SO 4 is closest to
(A) 3
(B) 2.7
(C) 2.4
(D) 2.1
TWO MARKS
YEAR 2009
Q. 27
A stroboscopic system is used for measuring the speed for a rotating shaft. The
shaft has on target mark on it. The maximum strobe rate at which synchronism is
achieved is r1 flashes per minute. The next lower flash rate at which synchronism
is achieved is r2 flashes per minute. The speed of the shaft in rpm is
(A) r1 r2
(B) r1 r2
r1 - r2
r1 + r2
(C)
Q. 28
(D)
r 12
r1 + r2
The fig. Shows the cross-sectional diagram of an orifice flow meter with an orifice
radius R. Point ‘a’ is 30 R upstream while points ‘b’ and ‘c’ are 0.8 R and 30 R
downstream from the orifice respectively. The pressures at points a, b and c are
Pa, Pb and Pc respectively. Then
(A)
(B)
(C)
(D)
Q. 29
r 22
r1 - r2
Pc > Pb > Pa
Pb > Pc > Pa
Pa > Pb > Pc
Pa > Pc > Pb
The values of the material constant b for thermistors P and Q are 4000 K and
3000 K, respectively. The resistance of each thermistor at 298 K is 2 kW. At 373
K the ratio of thermistor P to that of thermistor Q will be closest to
(A) 1.33
(B) 1.00
(C) 0.75
(D) 0.50
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Four strain gauges are fixed on a cylindrical shaft to measure tourque, as shown
in the figure.
Q. 30
(A) P-1, Q-2, R-3, S-4
(C) P-3, Q-1, R-2, S-4
(B) P-1, Q-3, R-2, S-4
(D) P-2, Q-1, R-3, S-4
Common Data For Questions 31 and 32 :
The figure shows an arrangement for measuring small angular displacements in a
vertical plane. A non-conducting tube of length 2l and rectangular cross section
(width W, height d) is bent along an arc of a circle with radius R>>d, centered
at P. Four electrode plates of length l and width W are placed to form two curved
parallel plate capacitors C1 and C2 with a negligible gap between them. The tube
contains water with an air bubble of rectangular cross section (width W, height
d) and length 1/4 the capacitors are connected in a bridge circuit as shown in the
figure, where the bridge has ac excitation Vi . Angular displacement Dq occurs
about the point P.
Q. 31
Q. 32
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The range of angular displacement (in radians) this system can measure is
(A) - I to + I
(B) - I to + I
8R
8R
4R
4R
(C) - 3I to + I
(D) - I to + I
4R
4R
R
R
V /V
The sensitivity 0 i is
Dq
(A) inversely proportional to R and I
(B) inversely proportional to R and directly proportional to I
(C) directly proportional to R and I
(D) directly proportional to R and inversely proportional to I
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YEAR 2008
ONE MARK
Q. 33
For signal conditioning of a piezoelectric type transducer we require
(A) a charge amplifier
(B) a differential amplifier
(C) an instrumentation amplifier
(D) a trans-conductance amplifier
Q. 34
The temperature being sensed by a negative temperature coefficient (NTC) type
(A) linearly increase with temperature
(B) exponentially increase with temperature
(C) linearly decrease with temperature
(D) exponentially decrease with temperature
YEAR 2008
TWO MARKS
Q. 35
The speed of a gear having 60 teeth is measured using a proximity sensor. The
output of the proximity sensor is fed to a counter with a gating of 1s. The counter
indicates a value of 120. The speed at which the gear is rotating is
(A) 60 rpm
(B) 120 rpm
(C) 600 rpm
(D) 1200 rpm
Q. 36
A piezoelectric type accelerometer has a sensitivity of 100 mV/g . The transducer
is subjected to a constant acceleration of 5g .The steady state output of the
transducer will be
(A) 0 V
(B) 100 mV
(C) 0.5 V
(D) 5 V
Q. 37
A par of identical thermo-couples is employed for measuring the temperature of a
speciman as shown. The characteristic is tabulated below. The reference junction
is at 2cC . The meter reads 48 mV . The correct temperature of the specimen is
Temperature
(cC)
(mV)
(A) 13cC
(C) 48cC
Output
Q. 38
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0
10
20
30
40
50 60
70
80
90
35
45
55
65
75
85 95
105
115
125
(B) 46cC
(D) 50cC
A strain gauge has a nominal resistance of 600 W and a gauge factor of 2.5 . The
strain gauge is connected in a dc bridge with other resistance of 600 W each. The
bridge is excited by a 4 V battery. If the strain gauge is subjected to a strain of
100 mm/m , the magnitude of the bridge output will be
(A) 0 V
(B) 250 mV
(C) 500 mV
(D) 750 mV
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Q. 39
The torque in a rotating shaft is measured using strain gauges. The strain gauges
must be positioned on the shaft such that the axes of the strain gauges are at
(A) 0c with respect to the axis of the shaft
(B) 30c with respect to the axis of the shaft
(C) 45c with respect to the axis of the shaft
(D) 90c with respect to the axis of the shaft
Q. 40
To reduce the effect of fringing in a capacitive type transducer
(A) the transducer is shielded and the shield is kept at ground potential
(B) a guard ring is provided and it is kept at ground potential
(C) the transducer is shielded and the shield is kept at the same potential as
the moving plate
(D) a guard ring is provided and it is kept at the same potential as the moving
plate
Q. 41
A 5 MHz acoustic pulse travels from a transducer through a 2 cm thick fat
tissue before it encounters and interface with a layer tissue at normal incidence.
The amplitude attenuation factors of fat and liver are 0.075 Npcm- 1 /MHz and
0.1Npcm- 1 / MHz respectively. The amplitude reflectivity coefficient of fat-liver
interface is 0.1. Taking both attenuation and reflection losses into a account, the
amplitude loss in (in dB) of echo pulse when it returns to the transducers is
(A) 0.74
(B) - 2.6
(C) - 6
(D) - 33
ONE MARK
YEAR 2007
Q. 42
Match the essential amplifier characteristics with the sensing applications given
below :
Sensing Applications
Amplifier Characteristics
P.
Charge amplifier with very low bias
current and high input impedance.
L
Q. Voltage amplifier with low bias current M
and very high input impedance.
R. Voltage amplifier with very high
CMRR.
(A) P-L, Q-M, R-N
(C) P-N, Q-L, R-M
Q. 43
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Strain gauge in unipolar DC
Wheatstone bridge.
Glass electrode pH sensor.
N
Piezoelectric sensor for
measurement of static force
(B) P-M, Q-N, R-L
(D) R-N, Q-M, R-L
The figure below shows various configuration of bonding a strain gauge to a
cantilever subjected to a bending force F.
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Which configuration given the maximum change in resistance for this force ?
(A) P
(B) Q
(C) R
(D) All have equal change in resistance
Q. 44
A Clark oxygen sensor is a
(A) Potentiometric sensor
(B) Amperometric sensor
(C) Conductometric sensor
(D) Magnetostrictive sensor
Q. 45
During intravascular measurment of arterial blood pressure, catheters may be
introduced in different configurations as shown in the figures below :
The static pressure will be measured correctly in the configuration (s)
(A) P and Q but not in R
(B) R only
(C) Q only
(D) P and R but not in Q
Q. 46
In N2 -washout estimation of lung volume using spirometry, the lung volumes at
the beginning and the end of the washout are the same. Let T, V, and F denote
temperature, volume and molar fraction (of N2 ) respectively; subscripts S and L
denote the spirometer and the lung; and t1 and t2 the beginning time and the end
time of the experiment, respectively.
Then
F (t ) V (t )
(A) VL = TL = s 2 s 2 G
TS FL (t1) - FL (t2)
F (t ) V (t )
(B) VL = TL = L 2 S 2 G
TS FL (t1) - FL (t2)
(C) VL = FL (t1) VL (t2)
(D) VL = TS FS (t2) VS (t2)
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Q. 47
Two sensors have measurement errors that are Gaussian distributed with zero
means and variance s12 and s22 , respectively. The two sensor measurements x1 and
x2 are combined to form the weighted average x = ax1 + (1 - a) x2, 0 # a # 1
. Assuming that the measurement errors of the sensors are uncorrelated, the
weighting factor a that yields the smallest error variance of x is
2
2
(A) 2 s2 2
(B) 2 s1 2
s1 + s2
s1 + s2
(C)
Q. 48
TWO MARKS
s2
s1 + s2
(D) 0.5
A well of cross-sectional area a w is connected to an inclined tube of cross-sectional
area at to form a differential pressure gauge as shown in the figure below. When
p1 = p2 the common liquid level is denoted by A. When p1 > p2 , the liquid level
in the well is depressed to B, and the level in the tube rises by l along its length
such that the difference in the tube and well levels is hd .
The angle of inclination q of the tube with the horizontal is
(A) sin- 1 : 1 - a w D
(B) sin- 1 :hd + at D
aw
hd at
l
(C) sin- 1 :hd - at D
(D) sin- 1 :hd + a w D
aw
at
l
l
Q. 49
The accompanying figure shows a VERTICAL venturimeter with upward water
flow. When the measured static pressure difference p1 - p2 , between the inlet and
the throat is 30 kPa, the flow rate is found to be 50 liters per second. Assume that
the coefficient of discharge remains the same.
When p1 - p2 = 20 kPa, the flow rate in litres per second, is
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(C) 40.8
TRANSDUCER,MECH.MEASUR.ANDINDUS.INSTRU.
(B) 39.3
(D) 54.2
Q. 50
A thermometer with time constant t, initially at the ambient temperature, is
used to measure the temperature of a liquid in a both. The excess temperature of
the thermometer and the liquid over the ambient are q (t) and ql (t), respectively,
where t denotes the time. If ql (t) = kt , where k is a constant, the steady state
error, defined as lim [q (t) - ql (t)], is
t"3
(A) 3
(B) 0
(C) - k
(D) - kt
Q. 51
In a laminar flow experiment, Fluid A is pumped through a straight tube and
the volumetric flow rate and pressure drop per unit length are recorded. In a
second straight tube having twice the internal diameter of the first one, Fluid B
records the same pressure drop per unit length at the same volumetric flow rate.
Assuming fully developed flow conditions in the tubes, the ratio of the dynamic
viscosity of Fluid B to that of Fluid A is
(A) 16
(B) 32
(C) 64
(D) 128
Q. 52
A thermistor has a resistance of 10 kW at 25cC and 1 kW at 100cC . The range of
operation is 0cC -150cC . The excitation voltage is 5 V and a series resistor of 1 kW
is connected to the thermistor
The power dissipated in the thermistor at 150cC is
(A) 4.0 mW
(B) 4.7 mW
(C) 5.4 mW
(D) 6.1 mW
Q. 53
A pH electrode, being used at 25cC , has a source resistance of 1010 W. The
electrode obeys the Nernst equation perfectly. The electronic voltmeter, with
which the potential is being measured, has an input impedance of 1011 W and a
gain of 100. If the pH of the analyte changes from 6.5 to 7.8, the change in voltage
observed on the voltmeter is
(A) less than 6.8 V
(B) between 6.8 V and 7.19 V
(C) Between 7.2 V and 7.49 V
(D) Greater than 7.49 V
Q. 54
A chamber is heated with a heater of maximum power rating of 1000 W . The
process transfer relationship between the steady state heater power and chamber
temperature is assumed to be linear with a slope of 2 W/cC . The heater power is
the sum of the output of a proportional controller having a proportional band of
200% and a constant offset of 500 W . The temperature achieved for a set point
of 300cC is
(A) 260cC
(B) 60cC
(C) 275cC
(D) 150cC
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Statement For Linked Answer Q. 55 and 56 :
Blood flow through a straight segment of an artery is measured using a Doppler
flowmeter. The probe is oriented at an angle of 45º to the longitudinal axis of the
artery. It is known that Doppler shift is proportional to the velocity of the blood in the
direction of propagation of sound from the prob and the frequency generated from the
probe. The velocity of sound in blood is 1500 m/s and the maximum blood flow velocity
to be measured is 110 cm/s .
Q. 55
Signal processing limitations constrain the maximum Doppler shift to be less
than 3 kHz . The maximum source frequency (probe output), to the nearest MHz,
should be
(A) 2 MHz
(B) 3 MHz
(C) 5 MHz
(D) 10 MHz
Q. 56
In above Q., If the piezoelectric crystal of the probe is made of quartz (Young’s
modulus Y = 80 # 109 N/m2 , r = 2.65 # 103 kg/m3 the maximum thickness of
the crystal required to resonate at the frequency determined above, to the nearest
mm, is
(A) 1 mm
(B) 2 mm
(C) 3 mm
(D) 4 mm
Statement For Linked Answer Q. 57 and 58 :
A push-pull capacitive displacement transducer is interfaced to a differential amplifier
and an ADC shown in the figure below.
Note that the bridge supply and the analog reference input for the ADC are derived
from the same 10 V DC source.
Q. 57
The change in capacitance for full-scale displacement is ! 5% for the capacitors.
The gain of the differential amplifier for utilization of the full range of the ADC
(which is ! 10 V ) is
(A) 10
(B) 20
(C) 30
(D) 40
Q. 58
If the supply voltage to the bridge decreases by 5% , the sensitivity of the
measurement system
(A) decreases by 5%
(B) does not change
(C) increases by 5%
(D) increase by 200%
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YEAR 2006
ONE MARK
“Veena Contracta” is the cross section where the flow area is a minimum for a
restriction type flowmeter. For an orifice meter, if d is the diameter of the orifice
opening, then the area of the vena contracta is approximately
2
2
(A) pd
(B) 0.99pd
4
4
Q. 59
2
(C) 0.8pd
4
2
(D) 0.6pd
4
A type J (iron-constant) thermocouple has a voltage sensitivity of 55 mV/cC
A digital voltmeter (DVM) is used to measure the voltage under the condition
shown in the following figure.
Q. 60
Given that T1 = 300cC, T2 = 100cC and T3 = T4 = 20cC , the meter will indicate
a voltage of
(A) 11.0 mV
(D) 15.4 mV
(C) 16.5 mV
(D) 17.6 mV
A Pirani gage measures vaccum pressure and works on the principle of
(A) Change in ionizing potential
(B) Change in thermal conductivity
(C) Deformation of elastic body
(D) Change in self-inductance
Q. 61
YEAR 2006
TWO MARKS
Statement For Linked Answer Q. 62 and 63 :
A capacitive type displacement transducer consist of two triangular plates, placed
side by side, with negligible gap in between them and a rectangular plate moving
laterally with an uniform air gap of 1mm between the fixed plates and the moving
plate. The schematic diagram is shown below with appropriate dimension.
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Q. 62
With the position of the moving plate shown in the figure above, the value of the
capacitance C1 and C2 thus formed are
(A) C 1 = 2.14 pF, C 2 = 1.29 pF
(B) C 1 = 14.17 pF, C 2 = 21.25 pF
(C) C 1 = 339 pF, C 2 = 212 pF
(D) C 1 = 18.16 nF, C 2 = 23.2 nF
Q. 63
The above sensor is incorporated in a capacitance measuring circuit as shown
in the following figure. Assuming ideal op amp, the output voltage under the
conditions mentioned above is
(A) 0.012 V
(C) 1.23 V
(B) 0.354 V
(D) 2.541 V
Q. 64
An accelerator has a seismic mass of 100 mg and natural frequency of 1 kHz , with
g the acceleration due to gravity, the static sensitivity of the accelerometer in
(nm/g) is
(A) 2.58 nm/g
(B) 9.81 # nm/g
2
(D) 6.28 # nm/g
(C) 7.28 # 10 nm/g
Q. 65
A glass plate is overcoated with a thin film as shown below. The reflectance of
the combination is monitored with a radiation of 600 nm wavelength. If ng and n f
are refractive indices of the glass plate and film material respectively with ng > n f
then reflectance reaches a minimum when the geometrical film thickness equals
(A) 600 nm
(C) 150 nm
YEAR 2005
Q. 66
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(B) 300 nm
(D) 100 nm
ONE MARK
The diameter of an aluminium sphere is found to be 50 mm at an atmospheric
pressure of 105 Pa. The bulk modulus for aluminium is 68.6 GPa. The change in
the diameter of the sphere in microns, when placed in vaccum is
(A) 0.018
(B) 0.024
(C) 0.032
(D) 0.038
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Q. 67
In a flyball-type angular speed magnitude measuring device, the centrifugal force,
given 10- 6 w2 , where w is the angular speed in rad/s, is transmitted to a spring
with the non-linear characteristic F = 16p2 x2 , where F is the applied force and x
is the spring compression in meters. The sensitivity of the device in mm.s is
(A) 1
(B) 1
p
2p
(C) 1
(D) 1
3p
4p
Q. 68
In a variable-area flowmeter (rotameter), the inlet tube diameter is the same as
that of the effective float diameter and the tube taper is small. When the volume
flow rate of a fluid is Q1 , the float stands at a height of 70 mm from the inlet and
when the volume flow rate of the fluid is Q2 , the float moves to a height of 20 mm
from the inlet. The ratio of the flow rates Q1 /Q2 is
(B) 0.29
(A) 3.5
(C) 0.082
(D) 12.3
Q. 69
In a falling-ball viscometer, the ball attains terminal velocities of 0.01 m/s for oil
A and 0.002 m/s for oil B. Assuming the oils have the same density and oil A has
kinematic viscosity of 5 # 10- 3 m2 /s , the kinematic viscosity of oil B in m2 /s is
(A) 15 # 10- 3
(B) 20 # 10- 3
(C) 25 # 10- 3
(D) 30 # 10- 3
Q. 70
A thermometer at room temperature 30cC is dipped suddenly into a bath of
boiling water at 100cC . It takes 30 seconds to reach 96.5cC . The time required
to reach a temperature of 98cC is
(A) 32.5 s
(B) 34.6 s
(C) 35.6 s
(D) 38.6 s
Q. 71
A control loop structure is shown in the figure with FC, FT, TC and TT denoting
Flow Controller, Flow Transmitter, Temperature Controller and Temperature
Transmitter respectively. This loop is an example of
(A)
(B)
(C)
(D)
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feed forward control
split range control
cascade control
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Q. 72
A temperature sensor having a range of 0-100cC has a worst case accuracy
specification of ! 1.0% of true or ! 0.3% of full scale, whichever is higher. The
sensitivity of the sensor is experimentally obtained by taking its readings at true
temperature 25cC and 75cC . The maximum error in sensitivity, expressed as
percentage of its ideal value is
(A) ! 0.105%
(B) ! 0.21%
(C) ! 1.05%
(D) ! 2.1%
Q. 73
A mercury barometer reads h mm Hg with the temperature of the mercury at T
cC . The barometer reading corrected for the standard temperature 0cC with b
denoting the volumetric expansion coefficient of mercury in 0cC- 1 is
h
(A)
(B) h (b + T)
1 + bT
(C) h (1 + bT)
(D) h (b - T)
Figure given below shows an ultrasound flowmeter with the transducers separated
by a distance L = 25 mm with the line joining the transducers making an angle 60c
with the direction of the flow. The transit time difference between upstream and
downstream measurements is 10 ns with the sound velocity in the medium being
1000 m/s. Assuming that the size of the transducers is very small as compared to
the diameter of the pipe, the flow velocity is
Q. 74
(A) 0.2 m/s
(C) 0.4 m/s
(B) 2 m/s
(D) 40 m/s
The two-wattmeter method is used to measure power in a balanced 3-phase
circuit, drawing lagging current. The power factor if one of the wattmeters reads
zero is
(A) 0.5
(B) 0.8
(C) 1.0
(D) 0
Q. 75
Common Data For Questions 76, 77 and 78 :
The temperature-emf characteristics of iron-constantan and copper-constantan
junctions, with the reference junctions at 0cC , are given by E1C = 5.3TmV and
ECC = 43TmV , over an appropriate temperature range, where T is in cC . It is
known that AD 590 is an IC temperature sensor with can drive a current of
(273 + T) mA at TcC into an appropriate load resistance.
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Q. 76
An iron-constantan thermocouple has its measuring junction in a both whose
temperature can vary between 100cC , the maximum error, expressed as a
percentage of the emf developed, due to ambient temperature variation in the
range 0cC , is
(A) 8.182
(B) 22.5
(C) 45
(D) 81.82
Q. 77
A thermocouple is made using a copper and an iron wire. Its measuring junction
is kept at a temperature of 100cC and the reference junction is kept at the
ambient temperature of 30cC . The emf developed would be
(A) 700 mV
(B) 1000 mV
(C) 3010 mV
(D) 5300 mV
Q. 78
A voltage generated using a AD 590 sensor is used to compensate for ambient
temperature error for the iron-constantan thermocouple in the circuit shown in the
figure such that the output voltage V0 is proportional to the measuring junction
temperature Tm . The values of RL and E for exact compensation, assuming ideal
components, are
(A) 1 kW, 273 mV
(C) 5.3 kW 1.447 V
(B) 4.3 kW, 1.174 V
(D) 1 kW, 303 mV
Common Data For Questions 79 and 80 :
A bonded metal strain gauge has the following specifications :
Gauge factor = 2.0
Unstrained resistance = 120 W at 0cC
Maximum operation temperature = 150cC
Temperature coefficient of resistance = (2 # 10- 5) cC- 1
Maximum tensile and compressive strain = 2 # 10- 2
Q. 79
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The temperature-induced resistance error at the maximum operating temperature
expressed as the percentage of resistance change due to maximum tensile strain
only, assuming self-heating effects to be negligible,is
(A) 0.0625
(B) 0.625
(C) 6.26
(D) 7.5
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Q. 80
TRANSDUCER,MECH.MEASUR.ANDINDUS.INSTRU.
Two strain gauges, with the specifications given above are mounted on a structural
member in a push-pull configuration, connected in a bridge along with two
standard resistances, whose output is fed to an amplifier as shown in the figure.
The output voltage V0 per unit battery voltage, under maximum loading, is
(A) - 04V
(C) 0.37 V
(B) - 0.37V
(D) 0.4 V
Q. 81
A cantilever type micro-accelerometer is designed by scaling down each dimension
of a macro-accelerometer by factor of 100. If the natural frequency of the macroaccelerometer is w when the natural frequency of the micro-accelerometer will be
(A) 100 w
(B) 10 w
(C) 0.1 w
(D) 0.01 w
Q. 82
A pressure sensor has the following specifications: Sensitivity at the
design temperature = 10 V/MPa , zero drift = 0.01 V/cC , sensitivity drift
= 0.1 ^V/MPa/cC h. When the sensor is used in an ambient temperature 20cC
above the design temperature, the output from the device is 7.4 V . The true value
of the temperature will be
(A) 0.71 MPa
(B) 0.68 MPa
(C) 0.65 MPa
(D) 0.61 MPa
Q. 83
The torque-speed curve of a constant field armature is controlled DC servometer
is shown in figure. The armature resistance in ohm and torque constant in N-m/A
of the motor respectively are
(A) 1.76, 0.68
(B) 1.75, 0.85
(C) 2.00, 0.25
(D) 0.01, 0.81
YEAR 2004
ONE MARK
Q. 84
A zero error in a vernier caliper is termed as
(A) accidental error
(B) systematic error
(C) interference error
(D) random error
Q. 85
Filtering is performed in surface finish measurement as a means of separating
roughness and wavines. In roughness measurement, the wavelengths that are
filtered out are
(A) half the cut-off wavelength
(B) shorter than the cut-off wavelength
(C) equal to the cut-off wavelength
(D) longer than the cut-off wavelength
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Q. 86
For a proving ring used in a press, the value of force and its uncertainty are given
as 12355 ! 2354 N without any rounding off. If the error should be rounded off at
the maximum to two significant figures only, the value of the reading is rounded
off as
(A) 12300 ! 2300 N
(B) 12360 ! 2350 N
(C) 12400 ! 2300 N
(D) 12400 ! 2400 N
Q. 87
A quartz peizo-electric type pressure sensor has a built in charge amplifier. The
sensor has a sensistivity of 1 mV/Pa. It is subjected to a constant pressure of 120
kPa. The output of the transducer at steady state is
(A) 0 mV
(B) 100 mV
(C) 120 mV
(D) 120 mV
Q. 88
A thermocouple can be considered as a single capacity system with a time constant
of 100 ms and unity gain. It is immersed in a heat bath whose temperature is
varying at 1cC/s from 0cC. When the actual temperature of the heat bath is 70c
C, the reading of the thermocouple will be
(A) 70.1cC
(B) 71cC
(C) 69.9cC
(D) 69cC
Q. 89
A viscous damper consists of a sliding piston and a cylinder filled with oil of
kinematic viscosity 5 # 10 - 5 m 2 /s. A damping force of 20 N is applied on the
piston and the steady state velocity reached is 10 mm/s. The damping co-efficient
of the damper is
(A) 2 Ns/mm
(B) 4 Ns/mm
(C) 10 Ns/mm
(D) 20 Ns/mm
Q. 90
To avoid the effect of fringing, the potential of the guard ring of a capacitance
transducer, shown in Fig. is to be made equal to
(A)
(B)
(C)
(D)
the ground potential
half of the excitation voltage
the voltage of the fixed plate
the voltage of the moving plate
YEAR 2004
Q. 91
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A device for measuring large internal diameters consists of two arms X and Y of
length 50 mm each and pivoted at A (Fig. Q.31). These are fitted with 3 equal size
rollers of diameter 10 mm. The arms are fitted with tilt sensors, which indicate
the angle of inclination of the arms with reference to the axis of gravity measured
in clockwise direction . If these angles of inclination of the arms X and Y are 90c
and 140c respectively, then the internal diameter of the measured device is
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(B) 118.6 mm
(D) 128.3 mm
(A) 110.6
(C) 120.3 mm
Q. 92
An outside micrometer having an anvil and spindle diameter of 6 mm is used for
measuring the diameter of a cylindrical part having a nominal diameter of 12
mm. During measurement, misalignment of the centerline of the work piece and
measuring instrument has occurred. If the tilt of the shaft axis is 3c then the error
in the measurement is
(A) 1, 74%
(B) 2.76%
(C) 2.32%
(D) 1.86%
Q. 93
A cylindrical piece ground on a center-less grinding machine is uniformly three
lobed. The contour of the lobed surface has the smaller radius r1 = 10 mm and
the larger radius r2 = 10.3 mm. The size of a truly circular ring gauge, which just
fits over this cylindrical pies, is
(A) 20.3 mm
(B)20.346 mm
(C) 20.465 mm
(D) 20.521
Q. 94
The calibration data for a pressure compensator of a pump is given below
Input x
0
1
2
3
4
5
6
7
8
9
10
Output y 9.5 8.4 7.8 7.4 6.1 5.4 5.2 4.6 3.2 1.9 1.1
For the given data, the slope of the best-fit line applying least square method is
(A) 0.921
(B) - 0.803
(C) 0.819
(D) - 0.945
Q. 95
A cantilever-type micro-accelerometer is designed by scaling down each dimension
of a macro-accelermeter by a factor of 100. If the natural frequency of the macroaccelerometer is w, then the natural frequency of the micro-accelerometer will be
(A) 100 w
(B) 10 w
(C) 0.1 w
(D) 0.01 w
Q. 96
A pressure sensor has the following specifications :
Sensitivity at the design temperature = 10 V/MPa, Zero drift = 0.01 V/cC,
Sensitivity drift = 0.01 (V/MPa)/cC
When the sensor is used in an ambient 20 cC above the design temperature, the
output from the device is 7.4 V. The true value of the pressure will be
(A) 0.71 MPa
(B) 0.68 MPa
(C) 0.65 MPa
(D) 0.61 MPa
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Q. 97
TRANSDUCER,MECH.MEASUR.ANDINDUS.INSTRU.
A variable capacitance angular velocity pickup is made with two concentrically
mounted parallel semicircular plates with a small separation between them as
shown in Figure. A dc voltage is connected across the terminals of the capacitance
sensor as shown. For a constant angular velocity w, the waveform of the current
i (t) will be
(A) dc
(C) triangular
(B) sinusoidal
(D) square
Q. 98
A strain gauge of resistance 120 W and gauge factor 2.0 is at zero strain condition.
A 200 kW fixed resistance is connected in parallel with it. Then the combination
will represent an equivalent strain of
(A) + 5290 mm/m
(B) zero
(C) - 123.8 mm/m
(D) - 300 mm/m
Q. 99
An iron-constantan thermocouple is to be used to measure temperature between
0 and 300cC. With reference junction at 0cC, the emf induced at 100cC and 300
cC are
E100 = 5268m V, E300 = 16325 mV
Then the nonlinearity at 100cC as a percentage of full scale is
(A) + 3.23%
(B) - 1.06%
(C) - 0.96%
(D) + 3.23%
Q. 100
A quarts clock employs a ceramic crystal with a nominal resonance frequency
of 32.768 kHz. The clock loose 30.32 s every 23 days. The actual resonance
frequency of the crystal is
(A) 32.7685 kHz
(B) 32.768 kHz
(C) 32.7675 kHz
(D) 32.7670 kHz
Q. 101
A single-sensor, contact-type ultrasonic flaw detector uses a frequency of 330 kHz.
When testing a specimen, an echo from a flaw is recorded 0.05 mass after the
transmitted pulse. If the velocity of sound in the test object is 6.0 km/s then the
flaw is at a depth of
(A) 120 cm
(B) 60 cm
(C) 30 cm
(D) 15 cm
Q. 102
An electromagnetic flowmeter is used to measure the average flow rate of a liquid
in a pipe of diameter 50 mm. The flux density in the liquid has peak value of
0.1 T. The output from the flowmeter is taken to an amplifier of gain 1000 and
input impedance of 1 MW. If the impedance of the liquid between the electrodes
is 200 kW, then the peak value of the amplifier output voltage for an average flow
velocity of 20 mm/s is
(A) 1.365 V
(B) 1 V
(C) 0.1 V
(D) 0.083 V
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Q. 103
TRANSDUCER,MECH.MEASUR.ANDINDUS.INSTRU.
The transmittance of a particular solution measured is T. The concentration of
the solution is now doubled. Assuming that Beer-Lambert’s law holds good for
both the cases, the transmittance of the second would be
(B) 2T
(A) T
2
(C) T2
Q. 104
(D)
T
In Fick’s method of cardiac output measurement, oxygen consumption is 200 ml/
min., arterial oxygen content is 0.30 ml/ml and venous oxygen content is 0.20 nl/
ml. The cardiac output in 1/min. is
(A) 1
(B) 2
(C) 0.5
(D) 1.5
YEAR 2003
ONE MARK
Q. 105
Which one of the following is a derived unit (NOT a basic unit) in SI system ?
(A) Candela
(B) Coulomb
(C) Kelvin
(D) mol
Q. 106
A Pirani gage sensor is used to measure pressure of the order of
(B) 1 MPa
(A) 10 MPa
(C) 100 Pa
(D) 1 Pa
Q. 107
Which of the following flow meters has the lowest pressure drop for a given range
of flow?
(A) Orifice meter
(B) Venturi meter
(C) Flow Nozzle
(D) Rotameter
Q. 108
Different types of transducers and signal conditioning circuits are given below.
Match the transducer with the appropriate signal conditioning circuit commonly
used with it.
P.
Thermocouple
1.
DC Bridge
Q. Strain gage
2.
Phase sensitive detector
R.
Piezoelectric
3.
Charge amplifier
S.
L.V.D.T
4.
Cold junction compensation
5.
Instrumentation amplifier
(B) P-1, Q-5, R-2, S-3
(D) P-4, Q-1, R-3, S-2
(A) P-2, Q-3, R-5, S-1
(C) P-4, Q-1, R-2, S-5
YEAR 2003
Q. 109
TWO MARKS
An RTD is assumed to be represented in the range 0cC to 100 cC by a linear
model as
RT = R0 (1 + 0.004 T)
where T is the temperature in cC.R0 = 100 W with a variation of !2W. The true
model of the RTD is
RT = R0 (1 + 0.004T + 6 # 10 - 7 T2)
The worst-case error magnitude in the resistance value that will be introduced, if
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the linear model is used over a range of 0 to 100 cC , is
(A) 2 W
(B) 2.8 W
(C) 3.0 W
(D) 3.4 W
Q. 110
Measurement of large external radius is possible with the help of an angle piece
and a screw gage as shown in Figure. The radius R can be expressed from the
measurement of H and q as
(A) Hsinq
1 - sinq
(C) Htanq
1 + sinq
Q. 111
(B) Hcosq
1 - cosq
(D) Hsinq
1 - cosq
A temperature-measuring instrument is modeled as a first order system with a
time constant of 5s. The sensor of the instrument is placed inside an oil bath whose
temperature has a sinusoidal variation with amplitude of 10 cC and a period of
20s around an average temperature of 200 cC. The sinusoidal component at the
output of the instrument will have amplitude.
(A) 0cC
(B) 5.37c C
(C) 8.27cC
(D) 10cC
Common Data For Questions 112 and 113 :
The table provides the thermo-emf sensitivity of five materials with reference to
platinum around 273 K
Material
Constantan
Nickel
Copper
Iron
Nichrome
Sensitivity
(mVK - 1)
- 35
- 25
+6
+ 18.5
+ 25
Q. 112
The thermocouple pair that gives the maximum sensitivity around 273 K is
(A) Platinum-Constantan
(B) Nichrome-Constantan
(C) Nickel-Constantan
(D) Copper-Nickel
Q. 113
Two copper-constantan thermocouples are connected such that the two constantan
wires are joined together. The two copper wires are connected to the input of a
low noise chopper stabilized differentials amplifier having a gain of 1000. One of
the thermocouple junctions is immersed in a flask containing ice and water in
equal proportion. The other thermocouple is at a temperature T. If the output of
the amplifier is 2.050 V, the temperature T is
(A) 205c C
(B) 102.5c C
(C) 51.25cC
(D) 50c C
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Q. 114
An N-type semiconductor strain gage has a nominal resistance of 1000 W and
gage factor of -100. The resistance of the gage, when a compressive strain of 100
mm/m is applied, is
(A) 900 W
(B) 990 W
(C) 1010 W
(D) 1100 W
Q. 115
A signal conditioning circuit suitable for a push-pull type capacitive transducer is
given in Figure. The output V0 is
(A) V- 0 = E C
3C
(C) V- 0 = E C - 3 C
C +3 C
Q. 116
(B) V- 0 = E 3 C
C
(D) V- 0 = E C + 3 C
C -3 C
A Piezoelectric transducer with a sensitivity of 2.0 pC/N having a capacitance
of 1600 pF and a leakage resistance of 1012 W is connected to a charge amplifier
as shown in Figure. If a force of 0.1 sin 10 t N is applied to the transducer, the
output-amplitude of the charge amplifier is
(A) 0.141 mV
(C) 1.414 mV
(B) 0.232 mV
(D) 1.732 mV
Q. 117
In a seismic acceleration sensor, with a displacement transducer as the secondary
element, decreasing the mass while maintaining all other parameters of the sensor
unchanged will
(A) reduce both natural frequency and steady-state sensitivity
(B) increase both natural frequency and steady-state sensitivity
(C) increase natural frequency but reduce steady-state sensitivity
(D) increase natural frequency without affecting steady-state sensitivity.
Q. 118
For a steady flow of liquid, the float of the rotameter will remain in a particular
position when
(A) drag force is balanced by weight of the float and buoyancy force
(B) weight of the float is balanced by the drag force and buoyancy force
(C) buoyancy force is balanced by the drag force and weight of the float
(D) drag force and buoyancy together is slightly greater than the weight of the
float
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Q. 119
A resistance RT of a resistive transducer is modeled as RT = R (1 - Kx), where
K is the constant of transformation and x the input quantity being sensed. The
resistor is connected to an ideal, opamp signal conditioning circuit of Figure. The
value of R is 100 W, K is 0.004 and x is 75. The output V0 is
(A) - 400 mV
(C) - 300 mV
Q. 120
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(B) - 4 mV
(D) + 600 mV
A cardiac output measurement set-up uses the thermo-diluation principle. The
change in the output temperature is 7cC for 5.60 litres per minute of cardiac
output with an integration time of 10 s. For a second measurement, with all other
parameters remaining unchanged, the change in the temperature is 10cC with an
integration time of 20 s. The cardiac output in litres per minute for this will be
(A) 5.60
(B) 4.21
(C) 3.92
(D) 1.96
YEAR 2002
ONE MARK
Q. 121
In the case of a variable reluctance type inductive transducer, push-pull
arrangement reduces non-linearity by eliminating
(A) the odd order harmonics
(B) the even order harmonics
(C) both odd and even harmonics
(D) offset
Q. 122
A seismic type of transducer has damping constant of 10. The transducer is
designed to measure
(A) acceleration
(B) velocity
(C) displacement
(D) force
Q. 123
A thermocouple is suddenly immersed in a medium of high temperature. The
approximate time taken by the thermocouple to reach 98% of the steady state
value is
(A) equal to the time constant of the thermocouple
(B) equal to twice the value of the time constant of the thermocouple
(C) equal to four times the value of the time constant of the thermocouple
(D) independent of the time constant
Q. 124
A capillary viscometer, with known dimensions, is used for measuring dynamic
viscosity of oil. In order to obtain viscosity, it is necessary and sufficient if one
measures
(A) pressure drop across the capillary
(B) volume of fluid collected in a given time
(C) Both A and B
(D) Not only A and B but also one must ensure that the flow is laminar
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Q. 125
The sensing element of a thermocouple at its hot junction is provided with a
shield while taking measurements in a high temperature gas. The principal reason
for providing the shield is
(A) to reduce conduction and convection errors
(B) to reduce radiation error
(C) to provide temperature compensation to the Seebeck voltage
(D) to improve air supply to the sensing element for better response
Q. 126
A pitot-static tube is used for measuring velocity of a gas, flowing in a duct. The
velocity is proportional to
(A) square root of the total pressure measured by the tube
(B) the total pressure measured by the tube
(C) difference between total and static pressures
(D) square root of the difference between total and static pressures
Q. 127
A temperature measuring system consists of a sensor and a thermal-well. Each
of them can be considered as a single capacity system with the capacity of the
thermal-well higher than that of the sensor. The overall measuring system will
(A) have equal time constants
(B) have zero damping
(C) be a non-interactive system
(D) be an interactive system
YEAR 2002
TWO MARKS
Q. 128
In a rotameter, used for measuring flow rate of a fluid, pa = pressure above the
float, pb = pressure below the float, A = area of float, V = volume of the float,
d1 = density of float material, d2 = density of the fluid, g = acceleration due to
gravity.
Which of the following equations describes the equilibrium of the float
(A) ^pb - pa h A = Vg ^d 2 - d1h
(B) ^pa + pb h A = Vg ^d2 + d1h
(C) ^pa - pb h A = Vg ^d2 - d1h
(D) ^pb - pa h A = Vg ^d2 + d1h
Q. 129
A quartz crystal (Young’s modulus E = 9 # 1010 N/m2 ) with piezoelectric
properties has a diameter of 10 mm and thickness of 2 mm . Its voltage sensitivity
constant is 4500 V/mm . If the voltage output is 127.3 V , the applied load is
approximately
(A) 100 N
(B) 200 N
(C) 127.3 N
(D) 6.4 N
Q. 130
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One method of measuring the radius of an arc ^Rh, is to allow a roller of radius
^r h to oscillate to and fro on the arc and measure the average time per oscillation
T second. The roller will then have a linear acceleration of 2g/3, where g is
acceleration due to gravity. In such an experiment, the value of radius of arc can
be found from the expression
(B) ^T 2 g/6p2h - r
(A) ^T 2 g/6p2h + r
(C) ^T 2 g/6p2h
(D) ^6r2 /T 2 g h
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YEAR 2001
Q. 131
ONE MARK
The pH value of a solution is 4. It indicates that concentration of hydrogen ions is
(A) 10-4 g/L and the solution is acidic
(B) 10-4 g/L and the solution is alkaline
(C) 10 4 mg/L and the solution is acidic
(D) 10-4 mg/L and the solution is alkaline
Q. 132
For flow measurement, a rotameter can be installed in a pipe line
(A) horizontally with flow inlet in a specific direction
(B) horizontally with flow inlet in any direction
(C) vertically with flow inlet at the bottom and the outlet at the top
(D) vertically with flow inlet at the top and outlet at the bottom
Q. 133
An example of a positive displacement flow meter is
(A) orifice meter
(B) rotary vane type meter
(C) turbine type meter
(D) ultrasonic flow meter
Q. 134
A gas chromatograph is used for
(A) measuring flow rate of a gas
(B) measuring the temperature of a gas
(C) measuring the pressure of a gas
(D) analysing the composition of a gas
YEAR 2001
Q. 135
TWO MARKS
In the context of transducers, identify the correct matches.
List I
List II
P. Mean free path
1. Optical pyrometer
Q. Humidity
2. Knudsen gauge
R. Heat transfer coefficient
3. Sling psychrometer
S. Intensity of radiation
(A) P-1, Q-2, R-3, S-4
(C) P-3, Q-4, R-1, S-2
4. Hot wire anemometer
(B) P-2, Q-1, R-4, S-3
(D) P-2, Q-3, R-4, S-1
YEAR 2000
Q. 136
The resistance temperature characteristics of a temperature transducer is shown
in figure. The transducer is
(A) nickel RTD
(C) platinum RTD
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ONE MARK
(B) NTC thermistor
(D) PTC thermistor
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Q. 137
TRANSDUCER,MECH.MEASUR.ANDINDUS.INSTRU.
Identify the correct set of matches from the following.
List II
List I
P. Electron capture detector
1. IR spectroscopy
Q. Scintillation counter
2. Oxygen analyser
R. Thermopile
3. Gas chromatography
S. Zirconia probe
(A) P-4, Q-1, R-2, S-3
(C) P-3, Q-1, R-4, S-3
Q. 138
4. Nuclear radiation spectroscopy
(B) P-2, Q-4, R-1, S-3
(D) None of the above
Identify the correct set of matches from the following.
List II
List I
P. LVDT
1. Reference junction compensation
Q. Piezoelectric crystal
2. Charge amplifier
R. pH probe
3. Phase sensitive detector
S. Thermocouple
(A) P-1, Q-3, R-4, S-2
(C) P-4, Q-1, R-2, S-1
Q. 139
4. High input impedance amplifier
(B) P-3, Q-2, R-4, S-1
(D) None of the above
Identify the correct set of matches from the following.
List I
List II
P. Pirani gauge
1. Temperature measurement
Q. Venturi meter
2. Vacuum pressure measurement
R. Radiation pyrometer
3. Force measurement
S.
4. Flow measurement
Load cell
(A) P-2, Q-1, R-4, S-3
(C) P-2, Q-4, R-1, S-3
YEAR 2000
(B) P-4, Q-3, R-2, S-1
(D) None of the above
TWO MARKS
Q. 140
Among the bonded metal strain gauges, the foil type is more popular than the
wire type because
(A) error due to transverse strain is much less in foil type
(B) gauge factor is much higher in foil type
(C) the foil type is much more insensitive to temperature variation
(D) None of the above
Q. 141
In a gas chromatograph, the gas which cannot be used as a carrier gas is
(A) helium
(B) nitrogen
(C) ammonia
(D) oxygen
Q. 142
Which of the following restrictors has the highest discharge coefficient?
(A) Orifice plate
(B) Flow nozzle
(C) Venturi tube
(D) None of these
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Q. 143
TRANSDUCER,MECH.MEASUR.ANDINDUS.INSTRU.
The characteristics of a control valve is shown in figure. The type of the valve is
(A) equal percentage
(C) quick opening
(B) linear
(D) None of these
**********
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ANSWER KEY
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